WASHINGTON — Most Washington scandals that end up on Capitol Hill tend to end the same way: with an apology.

Secret Service Director Julia Pierson will face lawmakers today for the first public accounting of the details surrounding an embarrassing and worrisome security breach at the White House earlier this month that, according to a congressman, was worse than the Secret Service has publicly acknowledged. The question is, will she follow the script?

At the very least, Pierson will have to explain how a man armed with a small knife managed to climb over a White House fence, sprint across the north lawn and dash deep into the executive mansion before finally being subdued. And she is certain to face tough questions about why members of Congress briefed by the agency apparently weren’t told of the full extent of the breach when she appears before the House Oversight and Government Reform Committee.

Rep. Jason Chaffetz, R-Utah, said Monday night that whistleblowers told his committee that the intruder ran through the White House, into the East Room and near the doors to the Green Room before being apprehended. They also reported to lawmakers that accused intruder Omar J. Gonzalez made it past a female guard stationed inside the White House, Chaffetz said.

“I’m worried that over the last several years, security has gotten worse — not better,” Chaffetz said.